1. Field of the Invention
The present invention relates to a switch device for use as, for example, a door mirror switch of a vehicle.
2. Description of the Related Art
An example of a conventional switch device of this type is disclosed in Japanese Patent Laid-Open Publication No. 11-288644, and is shown in FIGS. 10 and 11. FIG. 10 is a plan view of a conventional switch device, and FIG. 11 is a sectional view thereof.
A switch device 101 shown in FIGS. 10 and 11 is used for, by way of example, changing and adjusting the direction of a mirror surface of a left or right door mirror upward, downward, rightward, or leftward. The switch device 101 includes a push button 107 as a push operation body provided to an opening 105 of a switch case 103.
The push button 107 is provided with four convex portions 109 as markers corresponding to up, down, right, and left movements of the door mirror to indicate push operation portions. The push button 107 is also provided with a flange 111 in the opening 105.
The switch case 103 is provided with a wall 113 that surrounds the perimeter of the flange 111. The wall 113 stops a movement in a direction along the opening 105 of the flange 111 (such a movement is hereinafter simply referred to as a “lateral movement” in the drawing) to regulate a still position of the push button 107.
Between the push button 107 and the switch case 103, a spring 115 is provided to force the push button 107 to a position before pushing.
Correspondingly to each convex portion 109 indicating a push position, an actuator 117 is supported by the switch case 103 so as to be able to move in an axial direction. Provided at the bottom end of each actuator 117 is a rubber contact 119. The rubber contact 119 is provided with a movable contact 121. Opposite to the movable contact 121, a fixed contact 125 is provided to an electrical circuit board 123.
Thus, upon pushing any one of the convex portions 109 on the push button 107 for a tilting operation, the actuator 117 positioned at a side corresponding to this tilting is pressed to the axial direction to be moved, thereby deforming the rubber contact 119. With the deformation of the rubber contact 119, the movable contact 121 comes into contact with the fixed contact 125. With this contacting, a motor for operating the door mirror is driven via the circuit board 123, thereby allowing the direction of the door mirror to be changed and adjusted upward, downward, rightward, or leftward according to the pushing operation of the push button 107.
When no tilting operation is performed on the push button 107, the push button 107 keeps the still position in the opening 105 by a force of the spring 115. At this time, the wall 113 is adjacent to the outer perimeter of the flange 111, thereby allowing the still position of the push button 107 to be regulated by stopping the movement of the flange 111 by the wall 113.
However, the above-described structure poses problems such that, at the time of a tilting operation of the push button 107, a rubbing sound may occur and, due to a rubbing feeling, the feeling of operation is not good.
FIG. 12 shows the structure of a push button similar to that shown in FIGS. 10 and 11, and illustrates the state in which the push button 107 is pushed for a tilting operation.
As shown in FIG. 12, when the push button 107 is pushed at any of the convex portions 109, a force Fsinè occurs in a lateral direction with respect to a push operation force F. Therefore, the push button 107 is laterally moved in the direction of the force Fsinè with respect to the opening 105. Therefore, during the pushing operation, the flange 111 comes into contact with the wall 113 to cause the rubbing sound and the rubbing feeling as described above.